Today, the most successful games are action games like FPS, RPG, MMORPG...

I'd like to make a peaceful game, but I don't know how to attract people. I can make good graphics, but that's not the main thing that makes people like a game for more than a couple of minutes. The content is important. In the game styles mentioned earlier, their main content is fighting, killing others, and generally making yourself the most powerful player in the game.

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.
If this question can be reworded to fit the rules in the help center, please edit the question.

You don't bring up Minecraft, while violence is possible, it's hardly the main content. I'd also consider it pretty successful. I spend hours building stuff in creative or peaceful modes and enjoy myself immensely.
–
Karoly SJul 3 '12 at 17:21

Take a look at the XBOX game Fez. It is awesome! And of course, The World of Goo and Braid.
–
Martijn CourteauxJul 21 '12 at 13:04

Well, look around yourself. Good game designers see everything as a potential inspiration for a game mechanic, or an interesting aesthetic. I think that this pretty much answers it. Just look around you, and in other games, and see what interests you or other people!

But, here are some suggestions:

In general, boys like destruction (I'm quoting Jesse Schell on this), so maybe you should find a way to make it non-violent (physics/chemistry simulation? Minecraft-like TNT?)

Having any kind of power is a good feeling. Maybe you are a factory manager? A Sims City-like game can give a great sense of power, too.

Cooperation is interesting and is a primal instinct, thus, it's very good to make use of it. So, consider multiplayer!

Non-violent competition (competition being a primal instinct as well). Multiplayer gives you great posibillities here, as well.

(inspired by Byte's answer, and Jesse Schell) People also enjoy expression. Art, building, any kind of creative activity is great!

[Add almost any other noun from that Maslow's pyramid here]

So, the more basic urges or instincts you're able to satisfy, the better. See this updated Maslow's priority pyramid to find ideas (remember, games have the ability to satisfy even the lowest of these, and they use it all the time!):

One thing most posters seems to have forgotten is Exploration. Lot of people likes that, might it be exploring a country or a complicated crafting system.

You might want to check out the Bartle Test which is one of the first studies on what drives players in multiplayer games, there is non-peacefully parts but most of it can be used to think up a peacefully game (for example: exclude the 'killers' and what they like: 'interacting on other players in a harmful way' and make it 'interact on other players in a peacefully way').

OP will have 3-year-olds playing his games :D
–
jadkik94Jul 3 '12 at 14:00

1

@jadkik94 No, I won't have 3yo playing my games. But he's still right. Principles of fun are same for old like for young. People are playing games mostly because of relaxation and fun.
–
MiroAug 17 '12 at 23:15

I think games are very much like movies in a sense. And for a movie to be good it doesn't have to be violent.

The big difference between a game and a movie is the interactive part (obviously).
Also gamer's in general tend to want challenge and sometimes competition in games, which is not the case for movies.

But "necessary" mechanics of any game, violent or peaceful are:

Achievements: People need to chase something to stay interested, a (peaceful) game that hands you everything you can get from the start would get boring very fast.
Example: If you could plant everything in FarmVille the first minute.

Reward: Once they've reached this goal they need satisfaction for the work. This could be a new feature, new items, whatever. Getting rewarded in a game activates the brains reward mechanism, which can get physically addictive, just like a drug.

Scoreboard: In today's society where everyone is judged by everyone this seems to give players alot of satisfaction, even when the only benefit is to showoff/brag. This could be counted in the reward part aswell, but I decided to put them separate.

These are three very basic mechanics that can be implemented into pretty ANY game.
Now what you have to do is to decide what kind of a game you want to create, and based on that decide how you can implement all three of these mechanics to your game.

Other points i wont go deep into:

Cooperation: It's always fun to work togheter.

Competition: Always fun to beat your opponent.

Mystery: Keeps the player curious to what comes next.

I'll end the post there since it got very long, I hope this helps you to decide what kind of a game you want to create.

The important point to understand is that it is good to have conflict in stories and games, but conflict does not mean fighting, war, killing or things like that. Also, collaboration (in conflict or not) is more rewarding to players on the long term.

This is kinda backward. Conflict is necessary to build up tension, tension is required to make a compelling story. Violence is the easiest form of conflict. Most games try to tell a story and violence is the easiest way to archive that. You don't need to tell a story to make a game (a good story adds a lot the atmosphere though). The core component of a game still is the game-play. And the game-play rarely "needs" violence. For example a shooter could also be about a guy running through a parcour where he needs to hit all the targets once. Your game should be fun with or without violence, so think about that first and then think about violence. Not the other way arround.